Integrating Google chart with ExtJs 4-MVC

Hello forum members,

I have been working on a ExtJs 4 - MVC based project which looks almost like Complex dashboard example. I have a combobox which contains different types of charts like line chart, pie chart, bubble plot,geo chart etc. Whenever I select any chart from combobox I want to get respective chart in the center panel(border layout). I could able to implement line chart and pie chart using built-in chart APIs available for ExtJs. Now I want to integrate Google chart library with my application (For Ex: Google's bubble chart library ). After integrating the chart with EtxJs how do I implement click handling in google chart? Any help would be greatly appreciated.

PS: I'm a newbie to ExtJs. I still don't understand MVC in ExtJs completely. So detailed explanation would be really helpful.